There are cooks who swear that sprinkling roasted sichuan peppercorns to a dish can transform a simple dish to a very interesting one. For instance, if the dish known as salt and pepper pork is familiar to you, the pepper sprinkled over the pork in that dish is none other than Sichuan peppercorns.
What is sichuan peppercorn? Wikipedia says it is the “outer pod of the tiny fruit of a number of species in the genus Zanthoxylum (most commonly Z. piperitum, Z. simulans, and Z. schinifolium), widely grown and consumed in Asia as a spice. Despite the name, it is not related to black pepper or to chilies… [It has a] unique aroma and flavour that is not hot or pungent like black or white pepper, or chilies, but has slight lemony overtones and creates a tingly numbness in the mouth (caused by its 3% of hydroxy-alpha-sanshool) that sets the stage for these hot spices.”
Right. Not hot at all. And more than the flavor, it is the aroma that makes it incomparable.
Contrary to common belief, Sichuan peppers are not only important in Szechuan cuisine but is found in many Asian cuisines including Indonesian, Tibetan and Nepalese (or is it Nepali?). It is the rust-colored husks that are valued as spice and some say the seeds should be removed before the Sichuan peppercorns are added to food. That, I believe is only true if the Sichuan peppercorns are intended to be served on the side or as a garnish. If they are intended to be pounded or ground then added to the food while cooking, I see no reason why the seeds need to be removed.
Banned in the U.S. for allegedly containing a virus that is quite harmless to humans (the ban was more of a protectionist policy to favor certain sectors of the U.S. agriculture industry), the ban has been lifted after it was found out that heating Sichuan peppercorns at 160oF kills the virus.
More than a spice, the sichuan pepper is reputed to have medicinal uses as a blood purifier, digestive aid, a cure for certain kinds of skin allergy and even to get rid of tapeworms. Some warn though that heavy dosage may be toxic.